Mere-parsing with boundary and semantic driven scoping

ABSTRACT

Methods, systems and computer program products for implementing a mere-parser are disclosed. Text data is processed to generate one or more parse items. A boundary based attribute associated with one of the parse items is identified, and the identified mere attribute is associated with one or more of the remaining parse items that is not blocked from being associated with the boundary based attribute.

This application is a continuation of U.S. patent application Ser. No.11/735,278, filed Apr. 13, 2007, now issued as U.S. Pat. No. 7,908,552on Mar. 15, 2011, the content of which is hereby incorporated in itsentirety by reference.

TECHNICAL FIELD

The following disclosure relates to methods and computerized tools forparsing input text data.

BACKGROUND

Parsing generally involves processing input text data to obtain a listof parse items that may or may not represent known terms and phrases.Some parse items are associated with modifiers or attributes that tendto describe certainty or temporality of a word being modified. Inmedical coding, parse items tend to represent medical conditions withthe attributes providing appropriate modifications.

SUMMARY

Techniques for implementing a parser are disclosed.

In one aspect, text data is processed to generate one or more parseitems. A determination is performed to decide whether one or more of thegenerated parse items is associated with a boundary based attribute. Thedetermined boundary based attribute is associated with one or more ofthe other generated parse items that is not blocked from associatingwith the boundary attribute.

Implementations can optionally include one or more of the followingfeatures. The text data is processed to identify identifying one or moreboundary markers, and the parse items are generated based on theidentified boundary (mere) markers. Identifying the boundary markers caninclude identifying at least one from a group including a punctuationmark, a word, and a phrase. In addition, processing the text data caninclude normalizing the received text data to a predetermined textformat; morphologically processing the normalized text data to astandardized format; and identifying one or more phrases in themorphologically processed text data to be converted to anotherstandardized format. Further, associating the identified boundary basedattribute with one or more of the other generated parse items caninclude determining a direction to propagate the identified mereattribute across the ordered data structure. The determined directioncan include a linear direction to the left of the generated parse itemassociated with the identified boundary based attribute. Alternatively,the determined direction can include a linear direction to the right ofthe generated parse item associated with the identified boundary basedattribute. Alternatively, the determined direction can further include alinear direction to the left and a linear direction to the right of thegenerated parse item associated with the identified boundary basedattribute. The identified boundary based attribute can be propagated toassociate with one or more of the other generated parse items locatedalong the determined direction.

Implementations can further optionally include one or more of thefollowing features. Propagation of the identified mere attribute alongthe determined direction can be stopped or blocked when a competingboundary based attribute associated with one of the other generatedparse items is detected along the determined direction and the detectedcompeting boundary based attribute is of a type same as the identifiedboundary based attribute. Alternatively, the propagation can be blockedwhen a predetermined boundary marker is detected. Alternatively, thepropagation can be blocked by transforming the identified boundary basedattribute to an alternate boundary based attribute based on a detectionof a predetermined boundary marker or another boundary based attributeof some type other than that of the identified boundary based attribute.In addition, merging the generated parse items can include receiving apredetermined set of semantic definitions. Two of the generated parseitems can be individually compared separately against the received setof semantic definitions to obtain a first semantic match. Also, acombination of the two generated parse items can be compared togetheragainst the received set of semantic definitions to obtain a secondsemantic match. The first and second semantic matches can be compared todetermine whether the second semantic match is a better match than thefirst semantic match, and the two generated parse items can be mergedwhen detected that the second match is a better match.

Implementations can also optionally include one or more of the followingfeatures. A determination can be made to decide whether one or more ofthe generated parse items is associated with a semantic based attribute.One of the other generated parse items can be selected and comparedagainst a predetermined set of semantic definitions to obtain a firstsemantic match. Also, a combination of the identified semantic attributeand the selected one of the other generated parse items can be comparedtogether against the predetermined set of semantic definitions to obtaina second semantic match. The first and second semantic matches canfurther be compared to determine whether the second semantic match isbetter than the first semantic match. The determined semantic attributeis merged with the selected one of the other generated parse items whendetected that the second semantic match is better than the firstsemantic match. Further, merging the parse items can include forming alevel in a tree structure so that the parse items are children of amerged parse item created by their merger. Also, merging the semanticattribute with one or more of the remaining generated parse items caninclude processing the other generated parse items to determine apresence of another semantic attribute associated with one of the othergenerated parse items. A determination can be made to decide whether thedetermined another semantic attribute is of a type same as theidentified semantic attribute. Based on the determinations, theidentified semantic attribute can be stopped from being merged with theprocessed one of the other parse items when detected that the determinedanother semantic attribute is of the type same as the semanticattribute. Further, generating one or more parse items arranged in anordered data structure can include arranging the generated parse itemsin at least one from a group including a linked list, an array, a tree,a graph, a stack, and a heap.

The subject matter described in this specification can be implemented asa method or as a system or using computer program products, tangiblyembodied in information carriers, such as a CD-ROM, a DVD-ROM, asemiconductor memory, and a hard disk. Such computer program productsmay cause a data processing apparatus to conduct one or more operationsdescribed in this specification.

In addition, the subject matter described in this specification can alsobe implemented as a system including a processor and a memory coupled tothe processor. The memory may encode one or more programs that cause theprocessor to perform one or more of the method acts described in thisspecification.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

DESCRIPTION OF DRAWINGS

FIG. 1A is a functional block diagram of a mere-parser system.

FIG. 1B is a functional block diagram of a mere-parser system executingon a computer system.

FIG. 1C is a detailed view of a mere-parser application.

FIG. 2 is a flow chart of a process for implementing a parse itembounding system.

FIG. 3A is a flow chart of a process for implementing a linearpropagation system.

FIG. 3B is a flow chart showing a detailed view of a propagate attributeprocess.

FIG. 4A is a flow chart showing a detailed view of a tree buildingsystem.

FIG. 4B is a flow chart showing a scope parse item attribute process ofa tree building system.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Techniques for performing mere-parsing with both boundary (mere)condition rules based and semantic rules based propagation or scoping oflinguistic attributes are disclosed. While the following describestechniques in context of medical coding, some or all of the disclosedtechniques can be implemented to apply to any text or languageprocessing system.

Various implementations of a phrase parser, based on the use ofpunctuations, conjunctions, prepositions, articles, negatives andrelative pronouns, are described in U.S. Pat. No. 6,915,254(“Automatically Assigning Medical Codes Using Natural LanguageProcessing”), which is incorporated by reference in its entirety.Building upon the techniques described in the U.S. Pat. No. 6,915,254, aprocess of forming boundaries (or meres) that define parse items ofinput text data (e.g., a sentence or a phrase) is disclosed. Inaddition, techniques are implemented to determine the scope oflinguistic attributes that can be associated with remaining parse itemsin the input text data other than the ones in which the attributes areoriginally associated. The term “attribute” is broadly used in thisspecification to include a wide range of application dependent modifiersthat are not necessarily restricted to just adjectival or adverbialmodifiers. For example, an attribute can include various types, such ascertainty (e.g., possible, probable, ruled out), temporality (e.g.,history of, current, planned), etc. In addition, an attribute caninclude various application specific modifiers having a scope thatextends beyond the locally associated parse items.

The designation of a mere-parser is applied in this specification byusing the term, “mere” in context of dividing, limiting or bounding.Alternatively, the term, “mere” is used without qualification. Ratherthan analyzing sentences according to syntactic rules, a mere-parserestablishes boundaries with no syntactic analysis other than recognitionof the classes of the word(s) and/or marker(s) that are used toestablish boundaries within an input text data. For example, a sentencestructure can be quickly resolved into one or more bounded sections thatcan be reduced, scoped (or propagated), and reconstituted according toboundary and semantic based processes rather than standard syntacticprocesses.

In some aspects, the mere-parsing techniques as described in thisspecification is designed to be implemented in conjunction with (and maybe dependent on) methods of measuring the semantic correctness of apotential parse item. In particular, the mere-parsing techniques can beimplemented to function with techniques described in a copendingapplication Ser. No. 11/735,264, filed Apr. 13, 2007, entitled,“Multi-Magnitudinal Vectors with Resolution Based on Source VectorFeatures,” which is incorporated by reference in it's entirety.

Mere-Parser System Design

FIG. 1A is a functional diagram of a mere-parser system 100. Themere-parser system 100 includes a mere-parser application 132. Themere-parser application 132 can be implemented as a part of a sourcedata analysis unit 130. The source data analysis unit 130 and themere-parse application 132 are communicatively coupled to a source datastorage 140 and a semantic test application 110 through bi-directionalcommunication links 118 and 116 respectively. The source data storage140 is implemented to store source data 142. The semantic testapplication 110 is coupled to a semantic data storage 120 through abi-directional communication link 114. The semantic data storage 120 isimplemented to store semantic data 122. In some implementations, thesemantic test application 110 also includes a vector processingapplication 112, and the semantic data 122 includes target vector data124, which are implemented as part of a Multi-Magnitudinal Vector systemdescribed in the copending U.S. patent application Ser. No. 11/735,264,filed Apr. 13, 2007, entitled, “Multi-Magnitudinal Vectors withResolution Based on Source Vector Features,” incorporated by referencein its entirety.

FIG. 1B is a block diagram of the mere-parser system 100 implemented assoftware or a set of machine executable instructions executing on acomputer system 150 such as a local server in communication with otherinternal and/or external computers or servers 170 through acommunication link 155, such as a local network or the internet. Thecommunication link 155 can include a wired and/or a wireless networkcommunication protocol. A wired network communication protocol caninclude local wide area network (WAN), broadband network connection suchas Cable Modem, Digital Subscriber Line (DSL), and other suitable wiredconnections. A wireless network communication protocol can include WiFi,WIMAX, BlueTooth and other suitable wireless connections.

The computer system 150 includes a central processing unit (CPU) 152executing a suitable operating system (OS) 154 (e.g., Windows® OS,Apple® OS, UNIX, LINUX, etc.), a storage device 160 and a memory device162. The computer system can optionally include other peripheraldevices, such as an input device 164 and a display device 166. Thestorage device 160 can include nonvolatile storage units such as a readonly memory (ROM), a CD-ROM, a programmable ROM (PROM), erasable programROM (EPROM) and a hard drive. The memory device 162 can include volatilememory units such as random access memory (RAM), dynamic random accessmemory (DRAM), synchronous DRAM (SDRAM) and double data rate-synchronousDRAM (DDRAM). An input device can include a keyboard, a mouse, a touchpad and other suitable user interface devices. A display device 166 caninclude a Cathode-Ray Tube (CRT) monitor, a liquid-crystal display (LCD)monitor, or other suitable display devices. Other suitable computercomponents such as input/output devices can be included in the computersystem 150.

In some implementations, the mere-parser system 100 is implemented as aweb application (not shown) maintained on a network server (not shown)such as a web server. The mere-parser system 100 can be implemented asother suitable web/network-based applications using any suitableweb/network-based computer programming languages. For example C/C++, anActive Server Page (ASP), and a JAVA Applet can be implemented. Whenimplemented as a web application, multiple end users are able tosimultaneously access and interface with the mere-parser system 100without having to maintain individual copies on each end user computer.In some implementations, the mere-parser system 100 is implemented as alocal application executing in a local end user computer or asclient-server modules, either of which may be implemented in anysuitable programming language, environment or as a hardware device withthe application's logic embedded in the logic circuit design or storedin memory such as PROM, EPROM, Flash, etc.

Mere-Parser Application

FIG. 1C is a detailed view of the mere-parser application 132, whichincludes a parse item bounding system 134, a linear propagation system136 and a tree building system 138. The mere-parser application 132interacts with the semantic test application 110 through thebi-directional communication link 116. The parse item bounding system134 can be implemented using a combination of finite state automata(FSA) and context-free grammars (CFG), and the linear propagation system136 and the tree building system 138 can be implemented in C/C++.

Parse Item Bounding System Algorithm

FIG. 2 is a flow chart of process 200 for implementing the parse itembounding system 134. Given a source input text, which includes words,numbers, punctuations and white or blank spaces to be parsed, the parseitem bounding system 134 begins by normalizing the source input text toa standardized plain text format at 202. Normalizing to a standardizedplain text format can include converting the source input text, whichmay be in a word processor format (e.g., Wore), XML, HTML or some othermark-up format, to a plain text using either ASCII or some applicationdependent form of Unicode. The normalization process also includesdetecting and converting the white spaces so that words and punctuationin the source input text appear with a uniform type and uniform amountof white space between the words, punctuation and between paragraphs inthe source input text. In addition, the source input text is processedto preserve the page format and text alignments, and is represented in astandardized format.

The normalized input text is morphologically processed at 204 bymorphing the words, numbers, acronyms, etc. in the input text to one ormore predetermined standardized formats. Morphological processing caninclude stemming, normalizing units of measure to desired standards(e.g. SAE to metric or vice versa) and contextually based expansion ofacronyms. The normalized and morphologically processed input text isprocessed to identify and normalize special words or phrases at 206.Special words or phrases that may need normalizing can include words orphrases of various types such as temporal and spatial descriptions,medication dosages, or other application dependent phrasing. In medicaltexts, for example, a temporal phrase such as “a week ago last Thursday”can be normalized to a specific number of days (e.g., seven days) and anindication that it is past time.

At 208, the parse item bounding system 134 is implemented to identifyboundaries or boundary markers in the processed input text and parse theinput text to generate one or more parse items based on the identifiedboundary markers. The generated parse items are arranged in an ordereddata structure, such as a linked list of parse items ordered from leftto right. In some implementations, the data structure for representingthe bounded input text as an ordered list of parse items includesarrays, trees, graphs, stacks, heaps or other suitable data structurethat maintains an ordered view of the generated parse items. A boundarymarker may be one or more punctuation marks, words or patterns of words(e.g., conjunctions, prepositions, articles, negatives and relativepronouns.) In some implementations, boundaries can optionally includemodals and some limited set of application specific content words.

Once the parse items are generated, boundary based attributes thatpropagate are identified at 210. A boundary based attribute includes awide range of application dependent modifiers associated with one ormore of the generated parse items that are not necessarily restricted tojust adjectival or adverbial modifiers. In addition, a boundary basedattribute can be identified as one of various types such as certainty(e.g., possible, probable, ruled out), temporality (e.g., history of,current, planned), or other application specific attributes that mayhave scope that extends beyond the associated parse item. Further, wordsand/or punctuation patterns in the generated parse items are analyzed todetermine, to the degree possible, whether the identified attributeshould propagate (or associate) to the other parse items located to theleft, right or in both directions of the parse item associated with theidentified boundary based attribute. Some boundary attributes aredetermined to not associate with other parse items in the linked list.For example, a parse item that contains a propagating attribute beginswith a modal and is followed by the end of the linked list (e.g., aperiod that ends a sentence in the input text) is determined topropagate to the left of the parse item associated with the propagatingattribute. Each parse item is a data structure in a linked list that canlater become a tree. In addition, each parse item structure has anelement that contains the text of the parse item as well as elements tostore information about the feature that selected the boundary andinformation about the semantic content of the parse item as theinformation is identified.

Linear Propagation System Algorithm

FIGS. 3A and 3B are flow charts illustrating a process of implementingthe linear propagation system 136. The process is iterative and beginsby identifying the first parse item in the linked list of parse itemsgenerated from the processed input text at 302. A variable (i) is usedto keep track (e.g., by using a flag) of each parse item during theiteration. The variable (i) is initially set to “1” to indicate that thefirst parse item is being analyzed. The linked list of parse items isalso analyzed to determine the total number of parse items included inthe linked list at 304. A variable (y) is used to represent thedetermined total number of parse items. The linear propagating system136 iterates through the linked list, from the first parse item (e.g.,beginning of the input text) to the last parse item, testing each parseitem to determine whether the parse item (i) under analysis has apropagating attribute associated with the parse item at 306. If theparse item (i) under analysis is associated with a propagatingattribute, the attribute associated with parse item (i) is analyzed todetermine the direction of propagation (or association) at 308, 312 and316. If the direction of propagation is determined to be backward (left)308 toward the first parse item in the linked list, the attributeassociated with parse item (i) is further associated with the remainingparse items located to the left of the parse item (i) under analysis at310. Otherwise if the direction of propagation is determined to beforward (right) 312 toward the last parse item in the linked list, theattribute associated with parse item (i) is further associated with theremaining parse items located to the right of the parse item (i) at 314.Otherwise if the direction of propagation is determined to bebi-directional (i.e., both left and right) 316, the attribute associatedwith parse item (i) is further associated with the remaining parse itemslocated both to the right and left of the parse item (i) at 310 and 314respectively. If the parse item (i) is not associated with a propagatingattribute, the next parse item (i+1) in the linked list is identifiedand analyzed at 322 to determine whether the next parse item (i+1) isassociated with a propagating attribute at 306. Processes 308, 310, 312,314 and 316 are repeated for the next parse item (i+1) to determine thedirection of propagation as described previously. The iterative analysiscontinues until each and every parse item has been analyzed. When thevariable (i) is greater than (y), the linear propagation system 136determines that the last parse item has been analyzed at 324. Then theiteration ends at 326.

FIG. 3B is a flow chart further describing in detail the iterativeprocesses of associating the identified propagation attribute either tothe left 310 or the right 314. Propagating the attribute to the left 310or the right 314 is accomplished using one common iterative process. At330, a variable (j) is set to zero (j=0) and used to keep track of theother remaining parse items to potentially associate the identifiedpropagating attribute. At 332, the total number (y) of parse itemslocated in the direction of the parse item (i) is determined. If thedirection of propagation is determined to be left propagating at 334,the variable (i) is decremented (i=i−1) to indicate selection of thenext parse item immediately to the left (or in front) of the parse item(i) at 336. Otherwise, the direction of propagation is determined to beright propagating and the variable (i) is incremented (i=i+1) toindicate selection of the next parse item immediate to the right ofparse item (i). Once the variable (i) is either decreased 336 orincreased 338, the variable (j) is incremented (j=j+1) to indicate thatone of the remaining parse items in the left or right direction is beinganalyzed at 340.

The selected next parse item in the determined direction (either to theleft (i=i−1) or right of the parse item (i=i+1)) is analyzed todetermine whether the selected next parse item blocks association ofidentified propagating attribute at 342. If the propagating attribute isblocked at 342, then the iterative process to propagate the attributeends at 352. The criteria for blocking an attribute are applicationspecific. Using medical text application as an example, in the statement“The patient has possible COPD and probable pneumonia,” the rightpropagating attribute “possible” is blocked from associating with thenext parse item, “and probable pneumonia” by a preexisting attribute“probable” already associated with “and probable pneumonia.” In thisexample, the basis of blocking attribute is due to a competing attributeof the same certainty class or type already associated with the nextparse item. In addition, presence of certain boundary markers can blockattribute association and thus end the iteration. Punctuation marks(e.g., periods, question marks, exclamation marks, colons, etc.) are themost common boundary markers that can block propagation.

Alternatively, if the determination, parse item (i) blocks attribute342, evaluates to false, the selected next parse item is analyzed todetermine whether the selected next parse item transforms thepropagating attribute at 344. If the selected next parse item isdetermined to transform attribute, then the attribute is transformed at346 based on one or more features of the selected next parse item.Transforming the attribute 346 is also application specific. Continuingthe medical text example with the input text “The patient has possibleCOPD but not pneumonia,” the “but not” of the “but not pneumonia” wouldhave the effect of transforming “possible” to “not possible” or to amedically appropriate terminology, such as “ruled out.” Thus, boundarymarkers, such as conjunctions (e.g., “but”) and prepositions cantransform attributes. Once the attribute is transformed at 346, thetransformed attribute is associated with the selected next parse item at348. Otherwise, if the attribute is not determined to be transformed at344, the attribute is associated with the next parse item at 348 withoutbeing transformed. At 350, the variable (j) is compared to the variable(y) to determine if each and every remaining parse item in thedetermined direction has been analyzed. If the determination at 350 isreturned as true, then the iterative process ends. Otherwise, theiterative process is repeated beginning at 334 until either thebeginning or end of the linked list (or some other ordered list) of theparse items is reached.

Various classes of attributes are possible, depending on theapplication. Typically, attributes are modifiers that are not core tothe definition of the entries in a knowledge base (e.g., a target vectorset). In the example above, target vectors exist for “pneumonia” and“COPD”, but not for “possible pneumonia”, “probable pneumonia”, “ruledout pneumonia”, etc. “Possible”, “probable” and “ruled out” are insteadtreated as attributes that can attach to various medical conditions thatare described in the knowledge base. Attributes are classified accordingto both semantic similarity (e.g., the class, “certainty” can alsoinclude “possible,” “probable,” and “ruled out”) and also on shared setof blocking and transformation criteria. The criteria for blocking andtransforming attributes can be developed either manually or derived bysome automated process such as a statistical analyzer.

Tree Building System Algorithm

FIG. 4A and FIG. 4B are flow charts depicting a process of implementingthe tree building system 138, which includes two iterative processingblocks: a merge parse items process 400, and a scope parse itemattributes process 450. While FIG. 4A shows the merge parse itemsprocess 400 being performed before the scope parse item attributesprocess 450, the order of these two processing blocks is interchangeabledepending on the demands of the application. In some implementations,one or both of the process 400 and 450 can be repeated.

FIG. 4A shows the merge parse items process 400 in detail. The process400 processes (e.g., in an iterative manner) through the parse items inthe linked list (or other ordered structure) identified in the inputtext from left to right (or right to left, or top to bottom, etc.depending on the natural reading order of the language being processed)to test each adjacent parse item. At 402, the first parse item on thelinked list is identified and set to (i). The iterative process 400analyzes each of the parse items, starting from the first parse item(i), in the linked list against the immediately adjacent parse item,next (i), in a determined direction of iteration (either left or right).At 404, the merge parse items process 400 interacts with the semantictest application 110 to access a predetermined set of target semanticdata definitions 122 stored in the semantic data storage 120. The textof each parse item (i) and the adjacent parse item, next (i), arecompared against the target semantic data definitions 122 to obtainindividual semantic matches. Also, the combined text of the parse items(i) and next (i) is also compared against the target semantic datadefinitions 122 to obtain a merged semantic match. A determination ismade whether compared to the semantic match of either parse item (i) ornext (i), a better semantic match is obtained by combining parse items(i) and next (i). The determination of a better semantic match is basedon a test of the semantic goodness of the merged parse items as matchedagainst the items of the semantic data set 122 that determines whether amerger will be performed or not. If the determination at 404 is true,then the parse items (i) and next (i) are merged together. Otherwise, ifthe determination at 404 is false, then the iteration continues at 406by selecting the next two adjacent parse items.

Merging the parse items (i) and next (i) is performed by first creatinga new parse item (x) as a copy of the parse item (i) at 420. The newlycreated parse item (x) merged with the adjacent parse item, next (i) at422. Based on the merged parse items, a tree structure is constructed bysetting the parent of parse item (x) to parse item (i) and next (i) at424. A tree structure allows the hierarchical nature of a data structureto be represented in a graphical form. The names of relationshipsbetween nodes are modeled after family relations (e.g., parent andchildren). The starting node is often named the root. In a tree, aparent is a node that has one or more children nodes such that theparent of a child is one level closer to the root (i.e., at a higherlevel in the hierarchy) of the tree and each child has one and only oneparent node. Parse item (x) takes the place of parse item (i) in theparse item list at 430 by reassigning the next value for the parse itempreceding item (i) at 428, and assigning the next value for parse item(x) to the next value of next (i) at 426. When merging parse items, themanner in which semantic attributes are individually handled depends onthe type or class of the attribute. For example, ordinal modifiers maybe accumulated in a list as when merging parse items in the statement“fracture of the fifth, sixth and seventh left ribs.” Cardinals may besubjected to an application specific mathematical equation. For example,the lengths of wounds may be summed as required for medical coding. Ifthere is ambiguity or a conflict between any of the semantic attributesof the parse items being merged, such ambiguity is resolved by referenceto a priority hierarchy for each class of semantic attributes. When theend of the parse list is reached at 408, the iterative process continuesto the scope parse item attributes process 450. If the scope parse itemattributes process 450 has already been completed, then the iterativeprocess ends at 460.

In some implementations the iterative process 400 to merge parse itemscontinues until no more merges can take place. In addition, the numberof parse items being tested and merged can be varied (e.g., threeinstead of just two). Further, the process of merging attributes is notlimited to immediately adjacent parse items. The iterative process 400can be implemented to test and merge non-adjacent parse items (two ormore at a time).

FIG. 4B shows the iterative process of implementing the scope parse itemattributes process 450. Whereas the linear propagation system 136 dealswith attributes that are scoped (propagated) according to the boundarymarkers that define each parse item, the scope parse item attributesprocess 450 deals with attributes that are scoped based on semanticrules. For example, the two sentence fragments “lacerations andcontusions of the shoulder and thigh” and “headaches and contusions ofthe shoulder and thigh” are syntactically identical and thus both can bebounded to generate parse items in similar manners. However, a semanticanalysis of the two results in different number of medical conditions.The first sentence fragment yields four specific types of medicalconditions (“lacerations of the shoulder”, “lacerations of the thigh”,“contusions of the shoulder” and “contusions of the thigh”) whereas thesecond yields only three (“headaches”, “contusions of the shoulder” and“contusions of the thigh”). Broadly viewed, attributes thatscope/propagate according to boundary markers (bounding conditions) tendto be ancillary modifiers whereas semantically scoped attributes aremostly intrinsic to the definition of some condition or state of nature.

The scope parse item attributes process 450 iteratively processes all ofthe semantic attributes associated with the parse items in the linkedlist. At 454, the first parse item in the linked list is identified andassigned to variable (i). A determination is made at 472 to decidewhether the parse item (i) is associated with one or more semanticattributes. If the determination at 472 is true, then processes 456,458, 460, 462, 464, 466, 468 and 470 are performed to merge the semanticattributes with the parse items.

At 456, a variable (j) is also assigned to the first parse item. At 458,the scope parse item attributes process 450 interacts with the semantictest application 110 to access a predetermined set of target semanticdata definitions 122 stored in the semantic data storage 120. The textof the parse item (j) is compared against the target semantic datadefinitions 122 to obtain an individual semantic match. Also, thecombined text of the attribute (i) and the parse item (j) is alsocompared against the target semantic data definitions 122 to obtain amerged semantic match. A determination is made whether compared to thesemantic match of the parse item (j), a better semantic match isobtained by combining the attribute (i) and the parse item (j). Thedetermination of a better semantic match is based on a test of thesemantic goodness of the merged parse items as matched against the itemsof the semantic data set 122 that determines whether a merger will beperformed or not.

If the determination at 458 is true, then the attribute is merged withthe parse item (j). At 460, a copy of the parse item (j) is generatedand set to variable (x), and the attribute (i) is merged with parse item(x) at 462. Once the merger is accomplished, a tree is constructed bysetting parents of parse item (x) to attribute (i) and parse item (j) at464. Parse item (x) takes the place of parse item (j) in the parse itemlist by reassigning the next value for the parse item preceding parseitem (j) at 466. The iterative process continues by selecting the nextparse item (j=next (j)) at 468. Otherwise, if the determination at 458is false, then iterative merge process (456, 458, 460, 462, 464, 466,468 and 470) is not performed and the next parse item is selected at468. If the end of the parse item list is reached (j is end of list),then the iterative merge process ends for the semantic attribute (i).

If the determination at 472 is false (parse item (i) is not associatedwith one or more semantic attributes), then the process 450 iterates tothe next parse item (i) at 474 to determine whether that next parseitem, next (i), is associated with one or more semantic attributes. Ifthe end of the parse item list is reached at 476, the iterative process450 ends at 478. Otherwise, if there are still additional parse itemsremaining in the linked list, the iterative process 450 repeats from 472to analyze the next parse item, next (i).

In some implementations, the determination at 458 to test the semanticgoodness of a merger is blocked if parse item (j) already has a semanticattribute of the same type (e.g., certainty, temporality, etc.) as theattribute (i) that the iterative process 450 is attempting to merge.This, however, is primarily for the sake of enhancing processing speedrather than improving the quality of the linguistic processing. Consideragain the example described above in which “headache” has an anatomiclocation for the condition “ache” intrinsically associated with “head.”In such implementations, an attempt at matching “headache of theshoulder” or “headache of the thigh” is blocked on the basis that theanatomic site of “ache” is already defined. However, since neither“headache of the shoulder” nor “headache of the thigh” would have amedical definition, the only adverse effect of attempting a match may bethe added processing time that is wasted. In addition, the iterativeprocess 450 can be repeated until no further merges can take place.

While attributes are handled by the linear propagation system 136 andare tangential to the definitions in the knowledge base, the scopingthat takes place in the tree building system 138 handles the merging ofinformation that is core to the definitions in the knowledge base.Extending the example above to “mild lacerations and contusions of theshoulder and thigh”, the modifier “mild” is an attribute that scopes(propagates) to both lacerations and contusions. The scoping by whichthe system arrives at “shoulder lacerations”, “shoulder contusions”,etc. is semantically driven by the content of the knowledge base thatidentify “lacerations” and “contusions” as medical injuries, and“shoulder” and “thigh” as anatomic locations that can correctly be usedto specify the particular injuries. The line between attributes anddefinitional core knowledge, however, can at times be blurred. Forexample, adjectives such as “acute” and “chronic” are most often handledas attributes, but they are occasionally core to the definitions ofparticular medical conditions as in “chronic obstructive pulmonarydisease” (COPD). The multi-magnitudinal vector system as described inthe copending patent application Ser. No. 11/735,264, filed Apr. 13,2007, resolves this ambiguity, and further examples of attribute vs.core knowledge are also discussed in detail.

The data structure that results from the tree building system 138 is atree, the leaves of which are the original parse items for the inputtext (e.g., a sentence) and the level closest to the root is the finalresult of the tree building system 138. This data structure preserves atrace of the process with all original and intermediate data that may beuseful either for later processing or for system debugging. Otherstructures are possible, and preserving the original and intermediatedata is optional.

Computer Implementations

In some implementations, the techniques for implementing a mere-parseras described in FIGS. 1A to 4B can be implemented using one or morecomputer programs comprising computer executable code stored on acomputer readable medium and executing on the mere-parser system 100.The computer readable medium may include a hard disk drive, a flashmemory device, a random access memory device such as DRAM and SDRAM,removable storage medium such as CD-ROM and DVD-ROM, a tape, a floppydisk, a CompactFlash memory card, a secure digital (SD) memory card, orsome other storage device.

In some implementations, the computer executable code may includemultiple portions or modules, with each portion designed to perform aspecific function described in connection with FIGS. 1A to 4B above. Insome implementations, the techniques may be implemented using hardwaresuch as a microprocessor, a microcontroller, an embedded microcontrollerwith internal memory, or an erasable programmable read only memory(EPROM) encoding computer executable instructions for performing thetechniques described in connection with FIGS. 1A to 4B. In otherimplementations, the techniques may be implemented using a combinationof software and hardware.

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer, includinggraphics processors, such as a GPU. Generally, the processor willreceive instructions and data from a read only memory or a random accessmemory or both. The essential elements of a computer are a processor forexecuting instructions and one or more memory devices for storinginstructions and data. Generally, a computer will also include, or beoperatively coupled to receive data from or transfer data to, or both,one or more mass storage devices for storing data, e.g., magnetic,magneto optical disks, or optical disks. Information carriers suitablefor embodying computer program instructions and data include all formsof non volatile memory, including by way of example semiconductor memorydevices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks,e.g., internal hard disks or removable disks; magneto optical disks; andCD ROM and DVD-ROM disks. The processor and the memory can besupplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, the systems and techniquesdescribed here can be implemented on a computer having a display device(e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor)for displaying information to the user and a keyboard and a pointingdevice (e.g., a mouse or a trackball) by which the user can provideinput to the computer. Other kinds of devices can be used to provide forinteraction with a user as well; for example, feedback provided to theuser can be any form of sensory feedback (e.g., visual feedback,auditory feedback, or tactile feedback); and input from the user can bereceived in any form, including acoustic, speech, or tactile input.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of any invention or of what may beclaimed, but rather as descriptions of features that may be specific toparticular embodiments of particular inventions. Certain features thatare described in this specification in the context of separateembodiments can also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

A number of embodiments have been described. Nevertheless, it will beunderstood that various modifications may be made without departing fromthe spirit and scope of the claims. Accordingly, other embodiments arewithin the scope of the following claims.

What is claimed is:
 1. A computer system comprising a processor coupledto a memory, wherein the memory is encoded with computer executableinstructions that when executed cause the processor to: provide aplurality of parse items, the plurality of parse items based, at leastin part, on text data; provide an individual semantic match based, atleast in part, on a parse item of the plurality of parse items and a setof semantic data definitions; provide a merged semantic match based, atleast in part, on the parse item of the plurality of parse items and theset of semantic data definitions; provide a merged parse item responsiveto determining that the merged semantic match provides a better semanticmatch than the individual semantic match; and provide an ordered datastructure including the merged parse item and the plurality of parseitems.
 2. The computer system of claim 1, wherein the instructionsfurther cause the processor to: responsive to determining that the parseitem is associated with a propagateing attribute, associate thepropagateing attribute with another parse item of the plurality of parseitems.
 3. The computer system of claim 1, wherein the instructions toprovide a merged semantic match further cause the processor to: combinetext of the parse item and text of another parse item of the pluralityof parse items to provide combined text; and compare the combined textagainst the set of semantic data definitions to obtain the mergedsemantic match.
 4. The computer system of claim 1, wherein theinstructions to provide a merged semantic match further cause theprocessor to: combine text of the parse item and text of a semanticattribute to provide combined text; and compare the combined textagainst the set of semantic data definitions to obtain the mergedsemantic match.
 5. The computer system of claim 1, wherein theinstructions to provide a plurality of parse items further cause theprocessor to: normalize the text data to provide normalized text data;morphologically process the normalized text data to provide standardizedtext data; selectively convert at least one phrase of the standardizedtext data from a first standard to a second standard to provideprocessed text data; and identify boundary markers in the processed textdata to provide the plurality of parse items.
 6. The computer system ofclaim 1, wherein the instructions to provide a merged parse item furthercause the processor to merge adjacent parse items.
 7. The computersystem of claim 1, wherein the instructions to provide a merged parseitem further cause the processor to: copy the parse item to provide acopied parse item; merge another parse item of the plurality of parseitems with the copied parse item to provide the merged parse item; andreplace the parse item with the merged parse item in a linked list.
 8. Anon-transitory computer readable storage medium encoded withinstructions executable by a processor, the instructions comprising:providing a plurality of parse items, the plurality of parse itemsbased, at least in part, on text data; providing an individual semanticmatch based, at least in part, on a parse item of the plurality of parseitems and a set of semantic data definitions; providing a mergedsemantic match based, at least in part, on the parse item of theplurality of parse items and the set of semantic data definitions;providing a merged parse item responsive to determining that the mergedsemantic match provides a better semantic match than the individualsemantic match; and providing an ordered data structure including themerged parse item and the plurality of parse items.
 9. Thenon-transitory computer readable storage medium of claim 8, whereininstructions for providing a merged parse item include instructions formerging adjacent parse items.
 10. The non-transitory computer readablestorage medium of claim 8, wherein instructions for providing a mergedsemantic match include instructions for: combining text of the parseitem and text of another parse item of the plurality of parse items toprovide combined text; and comparing the combined text against the setof semantic data definitions to obtain the merged semantic match. 11.The non-transitory computer readable storage medium of claim 8, whereininstructions for providing a merged semantic match include instructionsfor: combining text of the parse item and text of a semantic attributeto provide combined text; and comparing the combined text against theset of semantic data definitions to obtain the merged semantic match.12. The non-transitory computer readable storage medium of claim 8,wherein instructions for providing a plurality of parse items includeinstructions for: normalizing the text data to provide normalized textdata; morphologically processing the normalized text data to providestandardized text data; selectively converting at least one phrase ofthe standardized text data from a first standard to a second standard toprovide processed text data; and identifying boundary markers in theprocessed text data to provide the plurality of parse items.
 13. Thenon-transitory computer readable storage medium of claim 8, wherein theinstructions further comprise: responsive to determining that the parseitem is associated with a propagateing attribute, associate thepropagateing attribute with another parse item of the plurality of parseitems.
 14. The non-transitory computer readable storage medium of claim13, wherein instructions for associating the propagating attribute withanother parse item of the plurality of parse items include instructionsfor: determining a direction of propagation of the propagatingattribute; and selectively associating the propagating attribute witheach parse item of the plurality of parse items associated with thedirection of propagation.
 15. The non-transitory computer readablestorage medium of claim 14, wherein instructions for selectivelyassociating the propagating attribute with each parse item of theplurality of parse items associated with the direction of propagationinclude instructions for selectively transforming the propagatingattribute.
 16. A method, comprising: providing a plurality of parseitems, the plurality of parse items based, at least in part, on textdata; providing an individual semantic match based, at least in part, ona parse item of the plurality of parse items and a set of semantic datadefinitions; providing a merged semantic match based, at least in part,on the parse item of the plurality of parse items and the set ofsemantic data definitions; providing a merged parse item responsive todetermining that the merged semantic match provides a better semanticmatch than the individual semantic match; and providing an ordered datastructure including the merged parse item and the plurality of parseitems.
 17. The method of claim 16, wherein said providing a merged parseitem comprises merging adjacent parse items.
 18. The method of claim 16,wherein said providing a merged semantic match comprises: combining textof the parse item and text of another parse item of the plurality ofparse items to provide combined text; and comparing the combined textagainst the set of semantic data definitions to obtain the mergedsemantic match.
 19. The method of claim 16, wherein said providing amerged semantic match comprises: combining text of the parse item andtext of a semantic attribute to provide combined text; and comparing thecombined text against the set of semantic data definitions to obtain themerged semantic match.
 20. A computer system comprising a processorcoupled to a memory, wherein the memory is encoded with computerexecutable instructions that when executed cause the processor to:identify a propagating attribute associated with a parse item of aplurality of parse items, the plurality of parse items arranged in anordered data structure; determine a direction of propagation of thepropagating attribute within the ordered data structure; and selectivelyassociate the propagating attribute with each parse item of theplurality of parse items located in the direction of propagation withinthe ordered data structure.
 21. The computer system of claim 20, whereinthe instructions to selectively associate the propagating attribute witheach parse item of the plurality of parse items located in the directionof propagation within the ordered data structure further cause theprocessor to associate the propagating attribute with each parse item ofthe plurality of parse items located in the direction of propagationwithin the ordered data structure until association of the propagatingattribute is blocked.
 22. The computer system of claim 20, wherein theinstructions to selectively associate the propagating attribute witheach parse item of the plurality of parse items located in the directionof propagation within the ordered data structure further cause theprocessor to selectively transform the propagating attribute.
 23. Thecomputer system of claim 20, wherein the ordered data structurecomprises a linked list and wherein the instructions to determine adirection of propagation of the propagating attribute within the ordereddata structure further cause the processor to determine whether thedirection of propagation of the propagating attribute is left, right, orbidirectional.
 24. The computer system of claim 20, wherein theinstructions to identify a propagating attribute associated with a parseitem of a plurality of parse items, the plurality of parse itemsarranged in an ordered data structure further cause the processor to:identify at least one boundary marker to provide the plurality of parseitems; and identify a modifier associated with the parse item of theplurality of parse items.
 25. The computer system of claim 24, whereinthe instructions to identify at least one boundary marker to provide theplurality of parse items further cause the processor to identify atleast one of a punctuation mark, a word, or a phrase.
 26. The computersystem of claim 20, wherein the instructions further cause the processorto replace the parse item with a merged parse item in the ordered datastructure, the merged parse item based, at least in part, on the parseitem.
 27. The computer system of claim 20, wherein the instructions todetermine a direction of propagation of the propagating attribute withinthe ordered data structure further cause the processor to: determine anumber of parse items of the plurality of parse items in a firstdirection of propagation; and determine a number of parse items of theplurality of parse items in a second direction of propagation.
 28. Thecomputer system of claim 20, wherein the instructions further cause theprocessor to arrange the plurality of parse items in a linked list. 29.A non-transitory computer readable storage medium encoded withinstructions executable by a processor, the instructions comprising:identifying a propagating attribute associated with a parse item of aplurality of parse items, the plurality of parse items arranged in anordered data structure; determining a direction of propagation of thepropagating attribute within the ordered data structure; and selectivelyassociating the propagating attribute with each parse item of theplurality of parse items located in the direction of propagation withinthe ordered data structure.
 30. The non-transitory computer readablemedium of claim 29, wherein instructions for selectively associating thepropagating attribute with each parse item of the plurality of parseitems located in the direction of propagation within the ordered datastructure include instructions for associating the propagating attributewith each parse item of the plurality of parse items located in thedirection of propagation within the ordered data structure untilassociation of the propagating attribute is blocked.
 31. Thenon-transitory computer readable medium of claim 29, whereininstructions for selectively associating the propagating attribute witheach parse item of the plurality of parse items located in the directionof propagation within the ordered data structure include instructionsfor selectively transforming the propagating attribute.
 32. Thenon-transitory computer readable medium of claim 29, wherein a type ofthe propagating attribute comprises at least one of a certainty type ora temporality type.
 33. The non-transitory computer readable medium ofclaim 29, wherein the instructions further include: receiving text data;normalizing the text data to provide normalized text data;morphologically processing the normalized text data to providestandardized text data; selectively converting at least one phrase ofthe standardized text data from a first standard to a second standard toprovide processed text data; identifying boundary markers in theprocessed text data to provide the plurality of parse items; andarranging the plurality of parse items in the ordered data structure.34. The non-transitory computer readable medium of claim 29, wherein theordered data structure comprises a linked list and wherein instructionsfor determining a direction of propagation of the propagating attributewithin the ordered data structure include instructions for determiningwhether the direction of propagation of the propagating attribute isleft, right, or bidirectional.
 35. A method, comprising: identifying apropagating attribute associated with a parse item of a plurality ofparse items, the plurality of parse items arranged in an ordered datastructure; determining a direction of propagation of the propagatingattribute within the ordered data structure; and selectively associatingthe propagating attribute with each parse item of the plurality of parseitems located in the direction of propagation within the ordered datastructure.
 36. The method of claim 35, wherein said selectivelyassociating the propagating attribute with each parse item of theplurality of parse items located in the direction of propagation withinthe ordered data structure comprises associating the propagatingattribute with each parse item of the plurality of parse items locatedin the direction of propagation within the ordered data structure untilassociation of the propagating attribute is blocked.
 37. The method ofclaim 35, wherein said selectively associating the propagating attributewith each parse item of the plurality of parse items located in thedirection of propagation within the ordered data structure comprisesselectively transforming the propagating attribute.
 38. The method ofclaim 35, wherein the ordered data structure comprises a linked list andwherein said determining a direction of propagation of the propagatingattribute within the ordered data structure comprises determiningwhether the direction of propagation of the propagating attribute isleft, right, or bidirectional.
 39. The method of claim 35, furthercomprising selectively merging the parse item of the plurality of parseitems with at least one of another parse item of the plurality of parseitems or a semantic attribute based, at least in part, on a plurality ofsemantic matches.
 40. The method of claim 35, wherein said identifying apropagating attribute associated with a parse item of a plurality ofparse items comprises: identifying at least one boundary marker toprovide the plurality of parse items; and identifying a modifierassociated with the parse item of the plurality of parse items.
 41. Themethod of claim 40, wherein said identifying at least one boundarymarker to provide the plurality of parse items comprises identifying atleast one of a punctuation mark, a word, or a phrase.